Ultrasonic scanners are commonly used in medical diagnostic testing to produce a two dimensional, cross sectional image of the body region being scanned. Needle guides have been releasably attached to ultrasonic scanners to orient a needle within a specific internal body part, such as a vein or artery. In such cases, the needle guide serves to axially align the tip of the needle within the scan plane at the focal zone of the ultrasonic scanner, so as the cross sectional image produced by the scanner reveals the tip of the needle in relationship to the internal body parts.
Numerous needle guides of various construction have been proposed. Amedic, Inc. of Phoenix, Ariz. manufactures a two part disposable needle guide with a groove extending along its length. A pivoting member covers the groove to secure the needle within the groove. There is no teaching to use a one-piece needle guide to perform the same function. U.S. Pat. No. 4,883,059 to Stedman describes a two part needle guide consisting of a grooved member and a cover to enclose the groove. U.S. Pat. No. 4,838,500 to Cooper describes an alternative construction of a two part needle guide. U.S. Pat. No. 4,469,106 to Harvi describes a needle guide with numerous interconnected members. None, however, describe a one-piece needle guide construction which guides and aligns the needle in a linear path at a predetermined angle with respect to the ultrasonic scanner, while also allowing the needle to be separated from the guide.